I use Amber Smalltalk to write cross-platform mobile apps for Android and iOS: https://medium.com/smalltalk-talk/amber-alert-we-can-do-mobi...
Smalltalk is not stuck as an academic language. Cincom and GemTalk would be very surprised to hear that. It is, and has been, used all around the world for commercial purposes for over three decades: https://medium.com/smalltalk-talk/who-uses-smalltalk-c6fdaa6...
It is possible to create shrink-wrapped distributables, but these days there really isn't much call for it. Most of the action is in the web and mobile space and IoT and so on.
Regarding performance, it was an issue prior to circa 1995, but today's hardware is more than fast enough. That's why Python and Ruby and Perl and Erlang are so popular, being no faster than Smalltalk.